4-amino-n, n-dialkyl-3-dialkylaminoanilines as developers for photographic silver halide emulsions



Patented Sept. 15, 1953 UNITED STATES PATENT (OFF 2,652,331 ICE 4-AMINO-N,N-DIALKYL-S-DIALKYLAMINO- ANILINES AS DEVELOPERS FOR PHO'IO- HALIDE EMULSIONS Arnold Weissberger and John R. Thirtle, Roch- .ester,N. Y., assignors to Eastman Kodak Com- GRAPHIC SILVER pany, Rochester, N. Y.

" Jersey a corporation of New N Drawing. Application December 15, 1951,

Serial N0. 261,912

,1 This invention relates to developing agents and developer compositions of use in photography and of particular use in color photography. Primary aromatic amino silver halide developing agents, such as the p-phenylenediamines, are well known. The simpler developing agents of this type have characteristically low develop ment rates for silver halide compared to other developing agents such as the aminophenols, and efforts have been made to increase the development rate by substitution of the aromatic nucleus or an amino group of the phenylene diamines. When thedeveloping agents are to be used for forming dye images in color photography it has been desirable that such increases in development rate, obtained by substitution of the parent componds, should not be accompanied by changes in light-absorption characteristics or color of the dye image obtained therefrom by coupling with a given coupler compound.

We havediscovered a class of substituted pphenylenediamine developing agents which surpass the large proportion of p-phenylenedia mines in developeractivity. In addition, when these developing agents are used in color-development processes of color photography, these developing agents possess very high coupling efii ciencies with well known coupler compounds to yield dye images without undesirable varia+ tions in lightabsor'ption characteristics.

The developing agents of the invention have the following general structure:

anilines but in contrast to such developing agents, our compounds, particularly the 3-dimethylamino-4-amino-N,N-dialkylanilines, show little or no tendency toward the mentioned variations in light absorption characteristics. That is, the former compounds having the 3-monoalkyl amino group, produce phenazonium dye images. with coupler compounds; and our com- 10 Claims. 01. -88) Example 1. -4 amino-mv-diethyz-semerituaminoaniline sulfate N,N-diethyl-3,4-dinitroaniline.

fuming nitric acid (sp. gr. 1.48) in 500 cc. of concentrated sulfuric acid is then added over a period of 1% hours, keeping the temperature at 8 to -10 C.

The mixture is stirred for2 hours longer, then poured onto 7 kg. of ice. After standing overnight, the mixture is filtered and the orange crystals washed until neutralto litmus. Two crystallizations from ethyl alcohol, the first in the presence of decolorizing charcoal, give 61.0 g. (25.6%), M.P. 94-50.

MAT-diethyl-3-dimethyldmino-4-nit1'oanili1te- A mixture of 15.0 g. (0.077 mole) of N,N-diethyl-3,4-dinitroaniline, 30 cc. of 25% aqueous dimethylamine and 150cc. of 95% ethanol was heated for three days in a pressure bottle at The, reaction mixture was concentrated and chilled in ice, giving 13.8 g. (92%) of orange crystals, M.P. 63.5-64.5".

4 amino-MN-Methyl-3-dimethylaminoaniline sulfate hydrate-A mixture of 7.1 g. (0.03 mole) of N,N diethyl-S-dimethylamino-4-nitroaniline and a liberal amount of Raney nickel catalyst in 60 cc. of absolute alcohol was shaken under 40 p. s. i. of hydrogen without heating. When re duction was complete, the catalyst was removed by filtration and the filtrate treated with 1.7 cc. (0.03 mole) of concentrated sulfuric acid in 10 cc. of 95% ethanol and 2 cc. of water. The salt was precipitated as a gum by addition of ether. After three days at 0 the solid was collected and slurried with absolute alcohol. The white powder was collected and dried in a vacuum desiccator over sulfuric acid. The yield was 6.6 g. (68%), MP. 107-109 C.

Example 2.--4-amino MN-dimetfiyl-3-dimethylaminoanilz'ne sulfate N,N-dimethyZ-3-4-dini- +HNO3 in a 2 l. Erlenmeyer flask is added all at. once 400 cc. of about 20% nitric acid at 20-25". The

flask is rotated slightly; until all of the nitro compound isdissolved. Then 600 cc. more of 20% nitric acid is, added" and, after mixingthe reactionisallowedto proceed for 1 00 4Lhours, preferably 1%; hours. The reaction mixture is diluted with 1 1. of cold water and'th'e crystals are collected on an 18-cm; Buchner'funneland washed with two 500-00. portions of coldwater, which may, be iollowed-by'careful washing'with cold acetone to remove polynitro compounds. The damp product is heated with 500 cc. of acetone for hour at reflux and'th'e' mixture is cooled at 0-5 for /2' hour. The ,orangecrystal's are-"collected on a Buchner' funnel and" washed carefully with 250 cc. of ice-cold acetone. The yield is 57-61 g-.; M. P. 177-178.

Dilution of the acetone filtrate with 500 cc. of water, chilling, collecting the precipitate, and recrystallizing from about 75 ccaof acetone gives 6.3-7.1 g. more product, melting at 177-1789. The total yield is 63.3-68.1 g. (Ml-53.6%)

N ,N -dimethyZ-3dimethylamino-4-nitroaniline Annixtureof 1016 g. (0105 mole) of"N;N-dimethyl-3;4 dinitroani1ine, 20 g. (0.441mole) of dimethylamine, and 25 cc. of". absolute ethanol was heated-in a sealed t'ubeatfl135"for Thours. The tube was. cooled to room temperature and opened. The contents ofthe' tube were chilled at 0 for .hour, following whichtheredcrystals were collectedanddried'. The yield was 3.6" g. (82.3%), MHPJ 79-8059. Dilutionof the filtrate gave 1.4g. more ofsatisfactory material; making the total yield 10.0 g. (95.6%.).

4'-amino-'-N,'N-dimethyl'-3 -dimethylamino'anili'rte C H: NH:

- under hydrogen at 45 p. s. i.

A mixture of 4.2 g. (0.02 mole) of NNdimethyl- 3-dimethylamino-l-nitroaniline and a liberal amount of Raney nickel in 50 cc. of absolute ethanol was warmed and shaken for 15' minutes The filtrate was treated immediately with 1.11 cc. (0.02 mole) of concentratedsulfuric acid in 10 cc. of ethanol andz'cc. of water. The salt crystallized on standing; at 0 for two days. The crystals were collected on a-Buchner funnel, washed with absolute alcohol, anddried in a vacuum desiccator overDrierite; The yield was 4.4 g. (72%).

Eammple 3.-4-amino-N,N-dimethyZ-3-diethylaminoa'niline 2A-dichloronitrobenzene-- is first prepared as follows-by the method of' Roberts and-.T-umer-, J. Chem; 800.127, 2004 (1925):

In a 500 cc. three-neck flask 190 cc. fuming nitric acid (density 1151') (450%. theory) isvig orously stirred'andikeptat 20-25 by a running tap water bath during the gradual additiont of 114 cc. m-dichlorobenzen'e"(onehour); The cl'ear red solution is transferre'dto'a steam bath; heated to 65-70", kept there for .ten minutes; and poured. with manual stlrrin'ginto a. mixture of 1500' g; cracked ice and IOO'Occ; water. Thergumimy yellowish solid isicoilect'ed" by suction'filtra tion', washed with water until free-ofa'cidf dissolved in 500 cc; methanol; Thecloudy'solution is filtered by suction and cooled tcrO? bythead dition of Dry Ice. The" product is' collected by suction filtration and dried in' air; the" faintly yellow needles weigh 93 g. (48% theory)" and melt at 3031;

5-chloro-N,N diethyl2 nitroaniline then prepared by a method similar'to' thatlof Holle= man and de Mooy; Re'c. trav. chim'., 35'; 3011916) as follows:

+Na0l -mclncr ysmo' 1 1 GO Nol- A In a 500cc; round-bottom flask 19121 g 2,4"- dichloronitrobenzene, 200" cc; diethylamin'e', and a solution of 5.5 g; anhydrous sodium carbonate in '70 cc. water are heated under reflux on the steam bath for24 hours. Sodium chloride is re moved by filtration; the filtrate is. allowed to evaporate (in a" hood) to a brown'oilwliich is dissolved in 300 cc. diethyl ether. The" ether solution is washed with cc; water whichis then extracted with 100 cc. ether; The combined ether phases are dried over sodium hydroxide, filtered, and distilled. A clear, light red oilis collected'at 93-98/2'mm1 weighing-1215 g; which 'isdissolved in 25 cc. methanol. The so'lutiomis cooled by the additionxofrDry'Iceto' -10'., mtered by suction. The product is washecbwith and melting at 30-31.

Analysis -L. o H 01 N CalculatediorCmHuGlNzOi -Q 52.5 5.7 15.5 12.2 Found; 52.5 5. 7 15.5 11.8

N,N-dimethyl-3-diethy1amino-4-nitroaniline is prepared by heating a mixture of 0.1 mole of the 5-chloro compound prepared above, 0.5 mole of anhydrous dimethylamine and 25 cc. of absolute alcohol in a sealed tube at 120 C. for 8 days. The solution is then diluted carefully with water and the crystals obtained from a non-polar solvent. The resultant product is then hydrogenated over Raney nickel catalyst and treated with sulfuric acid as described in the preceding examples to obtain the desired product, 4-amino-3- diethylamino-N,N-dimethylaniline sulfate.

Example 4.4 amino N,N-diethyl-3-diethylaminoaniline A mixture of 0.1 mole of 5-chloro-N,N diethyl-Z-nitroaniline and 0.5 mol of anhydrous diethylamine and 25 cc. of alcohol are heated as above in a sealed tube to obtain N,N-diethyl-3- diethylamino-4-nitroaniline. After purification of the product by recrystallization it is reduced as in the above examples to obtain the desired product 4-amino N,N diethyl-3-diethylaminoaniline.

The homologous 4-amino-N,N-dialkyl-3-dialkylaminoanilines contemplated by our invention are prepared in the manner of the above examples, preferably by the methods of Examples 3 and 4.

When used for the formation of colored photographic images, the developers of our invention may be used in conjunction with any wellknown coupler compounds such as those described in Fischer U. S. Patent 1,102,028, June 30, 1914; Mannes and Godowsky U. S. Patent 2,108,602, February 15, 1938; Mannes, Godowsky and Peterson U. S. Patent 2,115,394, April 26, 1938; and Mannes, Godowsky and Peterson U. S. Patent 2,126,337, August 9, 1938.

The following examples, which are illustrative only, indicate developing solutions which may be used according to our invention.

A. 3 g. 4-amino-3-dimethylamino N,N-diethylaniline sulfate; 0.5 g. sodium sulflte; 20 g. sodium carbonate; 1000 cc. water.

B. 2 g. 2-cyanoacetylcoumarone; 2.5 cc. 10% sodium hydroxide; 50 cc. ethanol.

B is added to A.

When it is desired to use the developing agents of the invention for development of black and white images in ordinary emulsions, or for development of colored images in emulsion layers containing color forming coupler compounds only composition A above may be used. The other developing agents contemplated by our invention are used similarly for formation of silver or dye images in emulsion layers.

The developing agents described in the present invention may be used to form photographic images by development of exposed silver halide contained in the usual gelatin carrier or in carriers such as collodion, water-permeable cellu-,

lose ester or synthetic resin.

What we claim is: 1. A developing solution for producing colored photographic images comprising as a silver halide developing agent, a compound having the general formula 1 group to form a colored image on development.

2. A developing solution for producing colored photographic images comprising 4-amino-N,N- dimethyl 3 dimethylaminoaniline as a silver halide developing agent, and a compound which.

couples with the oxidation product of said developing agent at the primary amino group to form a colored image on development. i

3. A developing solution for producing colored photographic images comprising 4-amino-N,N- diethyl-3-dimethylaminoaniline as a silver halide developing agent, and a compound which couples with the oxidation product of said developing agent at the primary amino group to form a colored image on development.

4. A developing solution for producing colored photographic images comprising 4-amino-N,N- dimethyl-3-diethylaminoaniline as a silver halide developing agent, and a compound which couples with the oxidation product of said developing agent at the primary amino group to form a colored image on development.

5. A developing solution for producing colored photographic images comprising 4-amino-N,N- diethyl-3-diethylaminoaniline as a silver halide developing agent, and a compound which couples with the oxidation product of said developing agent at the primary amino group to form a colored image on development.

6. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion containing a latent image, with a solution containing a compound having the general formula NH: wherein R and R1 each represent alkyl groups containing from 1 to 4 carbon atoms for a sumcient time to develop the latent image to a silver image.

7. A method of developing a silver halide emulsion which comprises treating an exposed silver halide emulsion containing a latent image, with a solution containing 4-amino-N,N- dimethyl-3-dimethylaminoaniline for a suflicient time to develop the latent image to a silver image.

8. A method of developing -a silver halide emulsion which comprises treating an exposed silver halide emulsion containing a. latent image, with a solution containing 4-amino-N,N-diethyl- 3-dimethy1amin0aniline for a sufiicent time to develop the latent image to a silver image.

a ena-#31 9. A method-yet developing a si1ver-- halide emulsion which comprises treating an exposed silver halide emulsion containingzwlatent;image, with a solution containing 4-amino-N,N-dimethyl-3-diethylaminoaniline for a sufiicient time to develop the latent-[image to a silver image.

10. A method of developirgig a silver halide emulsion which comprises treating an exposed 8; with a solution containing: 4-amino'-N;N-dia ethyl-3-diethylaminoaniline for asuificient timeato develop the latent image to a silver image. I r 1 ARNOLD WEISSBERGER. JOHN R. THIRTLE.

References Cited in the file of this patent Beilstein Handbuch der Org. I Chem.-,*' vol:

silver halide emulsion containing a latent image, 10 XIII, fined; (1930) p; 295; 

1. A DEVELOPING SOLUTION FOR PRODUCING COLORED PHOTOGRAPHIC IMAGES COMPRISING AS A SILVER HALIDE DEVELOPING AGENT, A COMPOUND HAVING THE GENERAL FORMULA 